Excitation properties of the divacancy in 4H-SiC
| Autor: | Nguyen Tien Son, András Csóré, Ivan Gueorguiev Ivanov, Andreas Gällström, Takeshi Ohshima, Björn Magnusson, Adam Gali |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Quenching
Condensed Matter - Materials Science Materials science Photoluminescence Silicon Ab initio chemistry.chemical_element 02 engineering and technology Electron 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Molecular physics law.invention chemistry law Excited state 0103 physical sciences 010306 general physics 0210 nano-technology Electron paramagnetic resonance Den kondenserade materiens fysik Excitation |
| Popis: | We investigate the quenching of the photoluminescence (PL) from the divacancy defect in 4H-SiC consisting of a nearest-neighbour silicon and carbon vacancies. The quenching occurs only when the PL is excited below certain photon energies (thresholds), which differ for the four different inequivalent divacancy configurations in 4H-SiC. Refined theoretical ab initio calculation for the charge-transfer levels of the divacancy show very good agreement between the position of the (0/-) level with respect to the conduction band for each divacancy configurations and the corresponding experimentally observed threshold, allowing us to associate the PL decay with conversion of the divacancy from neutral to negative charge state due to capture of electrons photoionized from other defects (traps) by the excitation. Electron paramagnetic resonance measurements are conducted in dark and under excitation similar to that used in the PL experiments and shed light on the possible origin of traps in the different samples. A simple model built on this concept agrees well with the experimentally-observed decay curves. Comment: 28 pages, 6 figures |
| Databáze: | OpenAIRE |
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